Hi, HS:
One comment inline
On Fri, 2016-09-30 at 16:56 +0800, Horng-Shyang Liao wrote:
> Hi CK,
>
> Please see my inline reply.
>
> On Fri, 2016-09-30 at 11:06 +0800, CK Hu wrote:
> > Hi, HS:
> >
> > On Mon, 2016-09-05 at 09:44 +0800, HS Liao wrote:
> > > This patch is first version of Mediatek Command Queue(CMDQ) driver. The
> > > CMDQ is used to help write registers with critical time limitation,
> > > such as updating display configuration during the vblank. It controls
> > > Global Command Engine (GCE) hardware to achieve this requirement.
> > > Currently, CMDQ only supports display related hardwares, but we expect
> > > it can be extended to other hardwares for future requirements.
> > >
> > > Signed-off-by: HS Liao <hs.liao@xxxxxxxxxxxx>
> > > Signed-off-by: CK Hu <ck.hu@xxxxxxxxxxxx>
> > > ---
> >
> > [snip...]
> >
> > > +
> > > +struct cmdq_task {
> > > + struct cmdq *cmdq;
> > > + struct list_head list_entry;
> > > + void *va_base;
> > > + dma_addr_t pa_base;
> > > + size_t cmd_buf_size; /* command occupied size */
> > > + size_t buf_size; /* real buffer size */
> > > + bool finalized;
> > > + struct cmdq_thread *thread;
> >
> > I think thread info could be removed from cmdq_task. Only
> > cmdq_task_handle_error() and cmdq_task_insert_into_thread() use
> > task->thread and caller of both function has the thread info. So you
> > could just pass thread info into these two function and remove thread
> > info in cmdq_task.
>
> This modification will remove 1 pointer but add 2 pointers. Moreover,
> more pointers will need to be delivered between functions for future
> extension. IMHO, it would be better to keep thread pointer inside
> cmdq_task.
>
> > > + struct cmdq_task_cb cb;
> >
> > I think this callback function is equal to mailbox client tx_done
> > callback. It's better to use already-defined interface rather than
> > creating your own.
>
> This is because CMDQ driver allows different callback functions for
> different tasks, but mailbox only allows one callback function per
> channel. But, I think I can add a wrapper for tx_done to call CMDQ
> callback functions. So, I will use tx_done in CMDQ v15.
Up to now, one callback function for one channel is enough for DRM. So
'different callback function for different sent-message' looks like an
advanced function. Maybe you should not include it in first patch.
Regards,
CK
>
> > > +};
> > > +
> >
> > [snip...]
> >
> > > +
> > > +static int cmdq_suspend(struct device *dev)
> > > +{
> > > + struct cmdq *cmdq = dev_get_drvdata(dev);
> > > + struct cmdq_thread *thread;
> > > + int i;
> > > + bool task_running = false;
> > > +
> > > + mutex_lock(&cmdq->task_mutex);
> > > + cmdq->suspended = true;
> > > + mutex_unlock(&cmdq->task_mutex);
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(cmdq->thread); i++) {
> > > + thread = &cmdq->thread[i];
> > > + if (!list_empty(&thread->task_busy_list)) {
> > > + mod_timer(&thread->timeout, jiffies + 1);
> > > + task_running = true;
> > > + }
> > > + }
> > > +
> > > + if (task_running) {
> > > + dev_warn(dev, "exist running task(s) in suspend\n");
> > > + msleep(20);
> >
> > Why sleep here? It looks like a recovery but could 20ms recovery
> > something? I think warning message is enough because you see the warning
> > message, and you fix the bug, so no need to recovery anything.
>
> My purpose is context switch to finish timer's work.
> I will replace it by schedule().
>
> > > + }
> > > +
> > > + clk_unprepare(cmdq->clock);
> > > + return 0;
> > > +}
> > > +
> >
> > Regards,
> > CK
>
> Thanks,
> HS
>
>
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